In Computed Tomography (CT) measures are in place to avoid that scatter photons impinge on the detector. To this end, so called anti-scatter grids have evolved to offer scatter attenuation on both angular (phi) and longitudinal (z) directions. However, despite such measures, sophisticated Monte Carlo based software corrections are required in order to completely eliminate the remaining artifacts caused by scatter events. This is particularly difficult in dual source systems, where sources influence each other's corresponding detectors with cross-scatter, i.e. photons from one source may impinge on the wrong detector due to scattering through the patient or object. Further, such anti-scatter corrections to some extent require a large degree of computation effort.
US 2004/114710 A1 discloses an X-ray CT apparatus including a plurality of X-ray irradiation sources and a plurality of X-ray detection units. Timing of irradiation of X-ray is shifted by each X-ray irradiation source, the detection unit separately obtains projection data and scatter correction data. In a scatter correction unit, scatter correction is performed based on the projection data and the scatter correction data.
US 2011/311019 A1 discloses a tomographic apparatus including at least two x-ray sources that are concurrently driven with different switching patterns to generate uniquely encoded radiation. The tomographic apparatus further includes at least two detectors that each detect primary radiation emitted by its corresponding one of the at least two x-ray sources and cross scatter radiation from at least one of the other at least two x-ray sources. Each of the at least two detectors produces an aggregate signal representative of the detected primary and cross scatter radiation. The tomographic apparatus further includes a decoupler which, based on the different switching patterns, identifies at least one signal corresponding to at least one of the at least two x-ray sources within the aggregate signal and associates the identified signal with its corresponding x-ray source.